In general, the taxiing phase of commercial aircraft is carried out by using the thrust of at least one of the airplane's main engines, and/or by towing the aircraft using a runway tractor.
Taxiing an airplane can be divided into two phases.
The first phase is the phase known in English as “taxi out”, i.e. the phase in which the airplane is heading away from the passenger boarding gate towards the threshold of the runway to take off:
During this phase the airplane leaves the terminal pushed backwards by a runway tractor and one or more of its main engines are operating.
Once the airplane is sufficiently far away from the terminal and positioned to move forward, the tractor is disconnected. The airplane then moves forward at low speed, using the thrust from one or more of its main engines, from the terminal to the threshold of the take-off runway. The airplane is then controlled by the pilot from the cockpit via the flight control unit.
The second phase is the phase known in English as “taxi-in”, i.e. the phase in which the airplane is heading from the landing runway to the terminal after landing:
In this phase, after landing, the airplane moves at low speed from the landing runway towards the terminal using the thrust of one or more of its main engines, under the control of the pilot in the cockpit, via the flight control unit.
When approaching the terminal, the airplane's movements may be guided by ground crew and, in case of congested traffic, the airplane may stop before the terminal and then be brought to the arrival gate by a runway tractor.
Taxiing airplanes using the current procedure is a source of significant costs for airlines.
These costs relate primarily to the use of jet engines for taxiing, since these are designed for the flight phase and therefore their operation is not optimal at low speeds and low power, resulting in over-consumption of kerosene.
The additional costs of maintenance and repair of damages caused by the jet blast when airplanes are too close to one another and by the ingestion of debris by jet engines during taxiing must also be taken into account.
Moreover, using jet engines for taxiing is also a source of noise pollution within the airport and causes emissions of polluting particles that affect local air quality and contribute to the greenhouse effect.
Furthermore, the current procedure makes the airplane dependent on runway tractors for reversing, as airplane jet engines generally do not allow backward movement.
This can lead both to delays when the tractors are not available and to costs linked to their use.
It is therefore desirable for companies to reduce their operational costs by optimizing the ground movement of airplanes. To achieve this, new taxiing procedures must be proposed to reduce kerosene consumption, shorten the duration of taxiing as well as reduce emissions of noise and polluting gases.
The solution proposed by the disclosed embodiments thus relates to an autonomous taxiing system, housed in or near the hubs or rims of the main or nose gear wheels of a commercial airplane.